The present invention relates to a manifold valve with a position detecting function for detecting an operating position of a solenoid valve placed on a manifold base by using a magnet and a magnetometric sensor.
There is a known solenoid vale in which an operating position of a spool can be detected by using a magnet and a magnetometric sensor as disclosed in Japanese Utility Model Application Laid-open No. 2-66784, for example. This solenoid valve is formed by mounting the magnet to an outer periphery of the spool and mounting the magnetometric sensor for sensing magnetism to a casing. When the spool moves to one switching position, the magnetometric sensor senses the magnet and is turned on. When the spool moves to the other switching position, the magnetometric sensor is separated from the magnet and turned off. The magnetometric sensor is connected to a controller by a lead which is led outside from the casing of the solenoid valve.
On the other hand, solenoid valves of this type includes one used as a manifold valve when it is placed on a manifold base. This manifold valve is normally formed by placing one or more solenoid valves on the manifold base such that pressure fluid and power are supplied together to the respective solenoid valves through the manifold base.
In such a manifold valve, similarly to the above-described known art, it is possible to detect the operating positions of the respective solenoid valves by using the magnet and the magnetometric sensor. In this case, however, it is necessary to route a conductor outside the casing and to introduce and connect the conductor into an electric connection portion of the manifold base if the magnetometric sensor is mounted to the casing of the solenoid valve like in the know art. As a result, problems such as burdensome and disorderly wiring and interference of the conductor with other members are likely to occur. Because the sensor connected by the conductor to the manifold base has to be detached from the casing or the conductor has to be cut off from the manifold base in order to separate the manifold base and the solenoid valve from each other in maintenance, handling is burdensome.
It is a technical object of the present invention to provide a manifold valve in which mounting of a magnetometric sensor is easy and wiring is easy and which is easy to handle in maintenance and has a position detecting function.
To achieve the above object, according to the invention, there is provided a manifold valve comprising a solenoid valve for controlling pressure fluid and a manifold base for supplying the pressure fluid and power to the solenoid valve.
The solenoid valve includes a casing having a mounting face for mounting the solenoid valve onto the manifold base, a valve member provided for sliding in the casing, solenoid-type driving means for driving the valve member, a magnet provided to move in synchronization with the valve member, and a depression in which a sensor is to be mounted and which is provided in a position of the mounting face of the casing corresponding to the magnet.
The manifold base includes a placing face on which the solenoid valve is placed, a first plug to be connected to a controller for controlling the solenoid valve, at least one magnetometric sensor disposed in a position on the placing face corresponding to the depression so as to project from the placing face toward the solenoid valve and fitted in the depression when the solenoid valve is placed on the placing face, and continuity means for making the magnetometric sensor and the first plug electrically continuous with each other.
In the manifold valve of the invention having the above structure, the magnetometric sensor is provided to the manifold base in the projecting state, the depression is formed in the casing of the solenoid valve, and the magnetometric sensor is mounted to the predetermined position in the depression by placing the solenoid valve on the manifold base. Therefore, mounting of the magnetometric sensor is easy and wiring is easy because the conductor does not need to be routed outside. Moreover, because it is unnecessary to detach the magnetometric sensor from the manifold base and to cut off the conductor from the manifold base in separating the manifold base and the solenoid valve from each other for maintenance, handling is easy.
According to a preferable structural mode of the invention, a projecting portion to be fitted in the depression is provided to the placing face of the manifold base and the projecting portion functions as positioning means in connecting the manifold base and the solenoid valve and as a holder for holding the magnetometric sensor projecting from the placing face by housing the magnetometric sensor in the projecting portion.
According to a concrete structural mode of the invention, the solenoid valve is a spool-type solenoid valve, the driving means is one or two solenoid-operated pilot valve(s), and the solenoid valve has on opposite sides of the valve member pistons respectively operated by operation of pilot fluid. The magnet is mounted to any of the valve member and the pistons.
In the invention, it is preferable that the magnet is mounted to be separated from the pressure fluid or the pilot fluid.
According to a concrete structural mode of the invention, each the piston has a pressure chamber formed on a side of one end face of the piston, a breathing chamber formed on a side of the other end face of the piston, and piston packing for separating both the chambers from each other and the magnet is mounted to a position of one of the pistons closer to the breathing chamber than to the piston packing in a state in which the magnet is prevented from coming in contact with the pilot fluid by the piston packing.